"""Version info, help messages, tracing configuration."""
import os
import sys
from argparse import Action
from typing import Generator
from typing import List
from typing import Optional
from typing import Union

import pytest
from _pytest.config import Config
from _pytest.config import ExitCode
from _pytest.config import PrintHelp
from _pytest.config.argparsing import Parser
from _pytest.terminal import TerminalReporter


class HelpAction(Action):
    """An argparse Action that will raise an exception in order to skip the
    rest of the argument parsing when --help is passed.

    This prevents argparse from quitting due to missing required arguments
    when any are defined, for example by ``pytest_addoption``.
    This is similar to the way that the builtin argparse --help option is
    implemented by raising SystemExit.
    """

    def __init__(self, option_strings, dest=None, default=False, help=None):
        super().__init__(
            option_strings=option_strings,
            dest=dest,
            const=True,
            default=default,
            nargs=0,
            help=help,
        )

    def __call__(self, parser, namespace, values, option_string=None):
        setattr(namespace, self.dest, self.const)

        # We should only skip the rest of the parsing after preparse is done.
        if getattr(parser._parser, "after_preparse", False):
            raise PrintHelp


def pytest_addoption(parser: Parser) -> None:
    group = parser.getgroup("debugconfig")
    group.addoption(
        "--version",
        "-V",
        action="count",
        default=0,
        dest="version",
        help="Display pytest version and information about plugins. "
        "When given twice, also display information about plugins.",
    )
    group._addoption(
        "-h",
        "--help",
        action=HelpAction,
        dest="help",
        help="Show help message and configuration info",
    )
    group._addoption(
        "-p",
        action="append",
        dest="plugins",
        default=[],
        metavar="name",
        help="Early-load given plugin module name or entry point (multi-allowed). "
        "To avoid loading of plugins, use the `no:` prefix, e.g. "
        "`no:doctest`.",
    )
    group.addoption(
        "--traceconfig",
        "--trace-config",
        action="store_true",
        default=False,
        help="Trace considerations of conftest.py files",
    )
    group.addoption(
        "--debug",
        action="store",
        nargs="?",
        const="pytestdebug.log",
        dest="debug",
        metavar="DEBUG_FILE_NAME",
        help="Store internal tracing debug information in this log file. "
        "This file is opened with 'w' and truncated as a result, care advised. "
        "Default: pytestdebug.log.",
    )
    group._addoption(
        "-o",
        "--override-ini",
        dest="override_ini",
        action="append",
        help='Override ini option with "option=value" style, '
        "e.g. `-o xfail_strict=True -o cache_dir=cache`.",
    )


@pytest.hookimpl(wrapper=True)
def pytest_cmdline_parse() -> Generator[None, Config, Config]:
    config = yield

    if config.option.debug:
        # --debug | --debug <file.log> was provided.
        path = config.option.debug
        debugfile = open(path, "w", encoding="utf-8")
        debugfile.write(
            "versions pytest-%s, "
            "python-%s\ncwd=%s\nargs=%s\n\n"
            % (
                pytest.__version__,
                ".".join(map(str, sys.version_info)),
                os.getcwd(),
                config.invocation_params.args,
            )
        )
        config.trace.root.setwriter(debugfile.write)
        undo_tracing = config.pluginmanager.enable_tracing()
        sys.stderr.write("writing pytest debug information to %s\n" % path)

        def unset_tracing() -> None:
            debugfile.close()
            sys.stderr.write("wrote pytest debug information to %s\n" % debugfile.name)
            config.trace.root.setwriter(None)
            undo_tracing()

        config.add_cleanup(unset_tracing)

    return config


def showversion(config: Config) -> None:
    if config.option.version > 1:
        sys.stdout.write(
            "This is pytest version {}, imported from {}\n".format(
                pytest.__version__, pytest.__file__
            )
        )
        plugininfo = getpluginversioninfo(config)
        if plugininfo:
            for line in plugininfo:
                sys.stdout.write(line + "\n")
    else:
        sys.stdout.write(f"pytest {pytest.__version__}\n")


def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
    if config.option.version > 0:
        showversion(config)
        return 0
    elif config.option.help:
        config._do_configure()
        showhelp(config)
        config._ensure_unconfigure()
        return 0
    return None


def showhelp(config: Config) -> None:
    import textwrap

    reporter: Optional[TerminalReporter] = config.pluginmanager.get_plugin(
        "terminalreporter"
    )
    assert reporter is not None
    tw = reporter._tw
    tw.write(config._parser.optparser.format_help())
    tw.line()
    tw.line(
        "[pytest] ini-options in the first "
        "pytest.ini|tox.ini|setup.cfg|pyproject.toml file found:"
    )
    tw.line()

    columns = tw.fullwidth  # costly call
    indent_len = 24  # based on argparse's max_help_position=24
    indent = " " * indent_len
    for name in config._parser._ininames:
        help, type, default = config._parser._inidict[name]
        if type is None:
            type = "string"
        if help is None:
            raise TypeError(f"help argument cannot be None for {name}")
        spec = f"{name} ({type}):"
        tw.write("  %s" % spec)
        spec_len = len(spec)
        if spec_len > (indent_len - 3):
            # Display help starting at a new line.
            tw.line()
            helplines = textwrap.wrap(
                help,
                columns,
                initial_indent=indent,
                subsequent_indent=indent,
                break_on_hyphens=False,
            )

            for line in helplines:
                tw.line(line)
        else:
            # Display help starting after the spec, following lines indented.
            tw.write(" " * (indent_len - spec_len - 2))
            wrapped = textwrap.wrap(help, columns - indent_len, break_on_hyphens=False)

            if wrapped:
                tw.line(wrapped[0])
                for line in wrapped[1:]:
                    tw.line(indent + line)

    tw.line()
    tw.line("Environment variables:")
    vars = [
        ("PYTEST_ADDOPTS", "Extra command line options"),
        ("PYTEST_PLUGINS", "Comma-separated plugins to load during startup"),
        ("PYTEST_DISABLE_PLUGIN_AUTOLOAD", "Set to disable plugin auto-loading"),
        ("PYTEST_DEBUG", "Set to enable debug tracing of pytest's internals"),
    ]
    for name, help in vars:
        tw.line(f"  {name:<24} {help}")
    tw.line()
    tw.line()

    tw.line("to see available markers type: pytest --markers")
    tw.line("to see available fixtures type: pytest --fixtures")
    tw.line(
        "(shown according to specified file_or_dir or current dir "
        "if not specified; fixtures with leading '_' are only shown "
        "with the '-v' option"
    )

    for warningreport in reporter.stats.get("warnings", []):
        tw.line("warning : " + warningreport.message, red=True)
    return


conftest_options = [("pytest_plugins", "list of plugin names to load")]


def getpluginversioninfo(config: Config) -> List[str]:
    lines = []
    plugininfo = config.pluginmanager.list_plugin_distinfo()
    if plugininfo:
        lines.append("setuptools registered plugins:")
        for plugin, dist in plugininfo:
            loc = getattr(plugin, "__file__", repr(plugin))
            content = f"{dist.project_name}-{dist.version} at {loc}"
            lines.append("  " + content)
    return lines


def pytest_report_header(config: Config) -> List[str]:
    lines = []
    if config.option.debug or config.option.traceconfig:
        lines.append(f"using: pytest-{pytest.__version__}")

        verinfo = getpluginversioninfo(config)
        if verinfo:
            lines.extend(verinfo)

    if config.option.traceconfig:
        lines.append("active plugins:")
        items = config.pluginmanager.list_name_plugin()
        for name, plugin in items:
            if hasattr(plugin, "__file__"):
                r = plugin.__file__
            else:
                r = repr(plugin)
            lines.append(f"    {name:<20}: {r}")
    return lines
